An FXS interface supplies ring, voltage, and dial tone for basic telephone equipment, keysets, and PBXs. An FXO interface is used for trunk, or tie line, connections to a PSTN CO or to a PBX that does not support E&M signaling (when local telecommunications authority permits). This interface is of value for off-premise station applications.
FXO and FXS interfaces indicate on-hook or off-hook status and the seizure of telephone lines by one of two access signaling methods: loop start or ground start. The type of signaling is determined by the type of service from the CO; standard home telephone lines use loop start, but business telephones can order ground start lines instead.
Configure
Configuration Examples and TechNotes
(All Telephony Signaling Configuration Examples and TechNotes)
(All Telephony Signaling Configuration Examples and TechNotes)
Caller ID Name Delivery Issues on Cisco IOS Gateways
Configuring and Troubleshooting the VIC-2DID
Configuring Hookflash Relay on FXS/FXO Voice Ports
High-Density Analog (FXS/DID/FXO) and Digital (BRI) Extension Module for Voice/Fax (EVM-HD)
Hookflash Transfer in MGCP
Ringing and Idle Voltages on Cisco FXS Interfaces
Using Analogue E&M Ports to Interface to Overhead Paging Systems
Configuring and Troubleshooting the VIC-2DID
Configuring Hookflash Relay on FXS/FXO Voice Ports
High-Density Analog (FXS/DID/FXO) and Digital (BRI) Extension Module for Voice/Fax (EVM-HD)
Hookflash Transfer in MGCP
Ringing and Idle Voltages on Cisco FXS Interfaces
Using Analogue E&M Ports to Interface to Overhead Paging Systems
Maintain and Operate
Troubleshoot and Alerts
Security Advisories, Responses and Notices
(All Telephony Signaling Security Advisories, Responses and Notices)
(All Telephony Signaling Troubleshooting TechNotes)
(All Telephony Signaling Security Advisories, Responses and Notices)
Cisco CallManager Input Validation Vulnerability
Cisco Security Advisory: XSS and SQL Injection in Cisco CallManager/Unified Communications Manager Logon Page
Troubleshooting TechNotesCisco Security Advisory: XSS and SQL Injection in Cisco CallManager/Unified Communications Manager Logon Page
(All Telephony Signaling Troubleshooting TechNotes)
Analog E&M Voice Signaling Overview
Cisco CallManager: Understanding Direct-Inward-Dial (DID)
Configuring and Troubleshooting the VIC-2DID
Ringing and Idle Voltages on Cisco FXS Interfaces
Troubleshoot Analog FXO GroundStart Outbound Call Failures
Troubleshooting Codec and Voice Card Complexity
Understanding and Troubleshooting Analog E&M Start Dial Supervision Signaling
Understanding Direct Inward Dial (DID) Voice Interface Cards
Understanding E&M Voice Interface Cards
Understanding Foreign Exchange Station (FXS) Voice Interface Cards
Understanding FXO Disconnect Problem
Understanding MGCP Interactions with Cisco CallManager
Understanding Why Telephones in the United Kingdom Connected to Cisco FXS Interfaces May Fail to Ring
WS-X6624-FXS: 24-Port FXS Blade for Catalyst 6000 Series Switches
Cisco CallManager: Understanding Direct-Inward-Dial (DID)
Configuring and Troubleshooting the VIC-2DID
Ringing and Idle Voltages on Cisco FXS Interfaces
Troubleshoot Analog FXO GroundStart Outbound Call Failures
Troubleshooting Codec and Voice Card Complexity
Understanding and Troubleshooting Analog E&M Start Dial Supervision Signaling
Understanding Direct Inward Dial (DID) Voice Interface Cards
Understanding E&M Voice Interface Cards
Understanding Foreign Exchange Station (FXS) Voice Interface Cards
Understanding FXO Disconnect Problem
Understanding MGCP Interactions with Cisco CallManager
Understanding Why Telephones in the United Kingdom Connected to Cisco FXS Interfaces May Fail to Ring
WS-X6624-FXS: 24-Port FXS Blade for Catalyst 6000 Series Switches
